User digital communication addresses such as internet or IP addresses are conventionally associated with a fixed physical location, similar to a user's business telephone line. However, portable communication devices such as laptop computers are becoming increasingly popular, and it is common for a user to access the internet from locations as diverse as hotel rooms and airplanes.
Digital communication networks are set up to route communications addressed to a communication or network address to an associated destination computer at an established physical location. Thus, if a laptop computer is moved to a remote location, communications to and from the laptop computer may not reach the new physical location.
For a computer (host) to communicate across a network (e.g., the internet), software protocols (e.g., Transport Control Protocol/Internet Protocol (TCP/IP)) must be loaded into the host. A host computer sends information (i.e., packets of data) to another destination computer via devices on the network (routers) which receive the packets and send the packets to the network or segment of the destination host. The destination host will route replies back using a similar process. Each host computer and router must therefore be configured to send the packets of data to an appropriate router to reach the intended destination. However, a router will receive the packets only if the host computers specifically send (address) the packets to that router at the link layer of the communication protocol. If a host is configured incorrectly (bad address or address of a router not on the local network), then the host computer and router will be unable to communicate, i.e., the router will not listen to the host or will “drop” packets.
With the advent of mobile computers (laptops) and the desire to plug them into various networks to gain access to the resources on the network and internet, a mobile computer must be reconfigured for each network. Traditionally this new configuration can be done either (i) manually in software on the mobile computer (usually causing the mobile computer to be restarted to load the new configuration), or (ii) with a new set of protocols which must be utilized on the mobile computer to obtain the configuration information from a device on the network to which the computer is being connected. When new services (protocols) are created to add functionality to the host computers, these new protocols may need to be updated in the host computers or routers, depending upon the type of new functionality being added.